Why is the thickness of annotation lines inconsistent in documents in PDF-XChange Editor?

Symptoms:

I have used the Rectangle Tool (or any other shape annotation tool) to add annotations to documents. There is no visible change in the document when the border thickness is changed from the default value of 1pt. However, when the document is previewed before printing, and when it is printed, the annotation lines are of the adjusted sizes.

Cause:

There is a Thin Lines setting (Ctrl+5) in PDF-XChange Editor that converts all annotation lines to a width of 1pt when they are viewed in documents. If the size of annotation lines does not change when the pt value is adjusted, then it is probable that the Thin Lines setting has been accidentally enabled.

This setting is included to assist in document editing - for example in cases where it is necessary for several lines to pass through the same point. If lines of a larger thickness are used in these cases then it may become problematic to see the desired line, or judge accurately the points of intersection, as detailed below:

Resolution:

When the Thin Lines feature is activated it is possible to view all lines completely and judge accurately where they intersect:

However, when documents that have the Thin Lines featured are displayed in the a print preview pane, they will display (and subsequently print) annotation lines at their actual size. This may cause a discrepancy in comparison to their appearance in the document when it is viewed in PDF-XChange Editor.

Therefore, open the document and press (Ctrl+5) to see if the Thin Lines setting is the issue.